1. Field of the Invention
The present invention relates generally to the art of processing polyurethane and more particularly to the art of providing effective release between polyurethane and other surfaces.
2. The Prior Art
U.S. Pat. No. 3,509,015 to Wismer et al discloses fabricating bilayer safety glass by casting a polyurethane film between a glass sheet and a mold coated with a release agent to facilitate separation of the polyurethane surface from the mold. No particular release agents are suggested.
U.S. Pat. No. 3,808,077 to Rieser et al discloses fabricating bilayer safety glass by assembling a preformed plastic sheet between a glass sheet and a mold coated with a release agent such as polyvinyl fluoride, polyethylene glycol terephthalate, organopolysiloxanes and high silica content glass resins.
U.S. Application Ser. No. 49,673 filed June 18, 1979 now U.S. Pat. No. 4,277,299 discloses laminating a preformed thermoplastic sheet to a glass sheet using a glass pressing mold with an optically smooth coating of a silicon-based polymeric release agent to facilitate separation of the laminate from the mold without impairing the optical quality of the plastic surface.
U.S. Application Ser. No. 65,797 filed Aug. 13, 1979 now U.S. Pat. No. 4,276,.350 discloses reducing the reactivity of a glass surface with a molecular layer of a fluorocarbon bonded to metal ions adsorbed at the glass surface.